The present disclosure relates to a diffractive optical element in which two optical members are stacked, and a diffraction grating is formed at an interface between the two optical members, and to an optical device including the diffractive optical element.
A diffractive optical element has been known, in which a plurality of optical members are stacked, and a relief pattern is formed at an interface between the optical members.
In a diffractive optical element described in, e.g., Japanese Patent Publication No. H09-127321, a plurality of optical members are stacked, and diffraction gratings having a saw-tooth cross section are formed at an interface between the optical members. More specifically, one of the diffraction gratings is configured so that a plurality of crest-like raised portions each having a vertical wall and a wall inclined to the vertical wall are arranged at a predetermined pitch, and the other diffraction grating is configured so that a plurality of valley-like recessed portions engaged with the raised portions are arranged at the same pitch as that of the raised portions.